THE EFFECTS OF MOLYBATE, TUNGSTATE AND lxd ON ALDEHYDE OXIDASE AND XANTHINE DEHYDROGENASE IN DROSOPHILA MELANOGASTER

1981 ◽  
Vol 23 (4) ◽  
pp. 597-609 ◽  
Author(s):  
M. M. Bentley ◽  
J. H. Williamson ◽  
M. J. Oliver

The effects of dietary sodium molybdate and sodium tungstate on eye color and aldehyde oxidase and xanthine dehydrogenase activities have been determined in Drosophila melanogaster. Dietary sodium tungstate administration has been used as a screening procedure to identify two new lxd alleles. Tungstate administration results in increased frequencies of "brown-eyed" flies in lxd stocks and a coordinate decrease in AO and XDH activities in all genotypes tested. The two new lxd alleles affect AO and XDH in a qualitatively but not quantitatively similar fashion to the original lxd allele. AO and XDH activity and AO-CRM levels appear much more sensitive to mutational perturbations of this gene-enzyme system than do XDH-CRM levels in the genotypes tested.

1982 ◽  
Vol 24 (1) ◽  
pp. 11-17 ◽  
Author(s):  
M. M. Bentley ◽  
J. H. Williamson

The effects of five new mal alleles on aldehyde oxidase (AO) and xanthine dehydrogenase (XDH) activities and CRM levels in Drosophila melanogaster are described. These alleles were isolated by taking full advantage of the pleiotropic phenotype exhibited by all previously described mal alleles and represent at least three unique examples of mal function. At least one of these alleles is a representative of a new complementation group. Two other alleles exhibit a wild-type eye color in homozygous stock and one of these is "leaky", exhibiting some 50% of the XDH activity normally found in Oregon-R control flies and some 12% of the AO activity. CRM and activity levels have been quantitated for both enzymes in all allelic heterozygotes. XDH-CRM levels vary only slightly around wild-type levels while AO-CRM levels appear much more sensitive to mutational alterations.


1979 ◽  
Vol 21 (4) ◽  
pp. 457-471 ◽  
Author(s):  
Michael M. Bentley ◽  
John H. Williamson

The isolation and characterization of 16 alleles of the cinnamon (cin, 1-0.0) locus in Drosophila melanogaster are described. The effects of cin on viability and the maternal effect of cin+ on eye color have been separated from each other as well as from the deficiency for aldehyde oxidase (AO) and xanthine dehydrogenase (XDH) activities. These 16 alleles have been assigned to four complementation groups based on analysis of AO and XDH activities in all heteroallelic female combinations. Zygotic complementation for lethality and eye color has been characterized and allows the ordering of cin alleles in a consistent pattern for the ability to produce viable zygotes and/or complement for the eye color phene. Several complementing cin combinations were analyzed for heat stability of AO. In all cases, AO from allelic heterozygotes was more heat labile than wild-type AO. One cin allele, cin13, produces heat labile AO in combination with cin+ from Oregon-R, hence exhibiting a "dominant" heat stability phenotype.


Genetics ◽  
1989 ◽  
Vol 123 (3) ◽  
pp. 503-509 ◽  
Author(s):  
A G Reaume ◽  
S H Clark ◽  
A Chovnick

Abstract The rosy (ry) locus in Drosophila melanogaster codes for the enzyme xanthine dehydrogenase. Mutants that have no enzyme activity are characterized by a brownish eye color phenotype reflecting a deficiency in the red eye pigment. This report demonstrates that enzyme which is synthesized in some tissue other than the eye is transported and sequestered at the eye. Previous studies find that no leader sequence is associated with this molecule but a peroxisomal targeting sequence has been noted, and the enzyme has been localized to peroxisomes. This represents a rare example of an enzyme involved in intermediary metabolism being transported from one tissue to another and may also be the first example of a peroxisomal protein being secreted from a cell.


Genome ◽  
1993 ◽  
Vol 36 (1) ◽  
pp. 162-165 ◽  
Author(s):  
James M. Humphreys ◽  
Arthur J. Hilliker ◽  
John P. Phillips

We have previously shown that homozygous mutants of Drosophila melanogaster deficient in the oxygen radical scavengers, CuZn superoxide dismutase or urate, are adult viable and yet hypersensitive to the oxygen radical-generating agent, paraquat. Thus, paraquat could be used as a selective agent to identify adult-viable mutants potentially defective in other, perhaps unknown, oxygen defense functions. Here we report the successful use of paraquat hypersensitivity in the isolation of X-linked, ethylmethanesulfonate-induced mutations affecting oxygen defense in Drosophila melanogaster. Two paraquat hypersensitive mutants were identified that, by complementation analysis, were shown to be new alleles of the maroon-like gene. In addition to paraquat hypersensitivity, both alleles confer a maternally affected dark brown eye color and a complete lack of enzymatically active xanthine dehydrogenase, both of which are characteristic phenotypes of known maroon-like alleles. We conclude that the lack of xanthine dehydrogenase in these mutants leads to the absence of urate, which is the proximate cause of paraquat sensitivity. Because our search for such mutants on the X chromosome revealed two alleles of only a single selectable gene, we anticipate that the total number of major oxygen defense genes in the complete Drosophila genome may not be large.Key words: paraquat, maroon-like, xanthine dehydrogenase, oxygen defense.


Genetics ◽  
1979 ◽  
Vol 91 (4) ◽  
pp. 695-722
Author(s):  
Victoria Finnerty ◽  
George Johnson

ABSTRACT Xanthine dehydrogenase (XDH) and aldehyde oxidase (AO) in Drosophila melanogaster require for their activity the action of another unlinked locus, maroon-like (mal), While the XDH and A 0 loci are on chromosome 3, mal maps to the X chromosome. Although functional mal gene product is required for XDH and A 0 activity, it is possible to examine the effects of mutant mal alleles in those cases when pairs of mutants complement to produce a partial restoration of activity. To test whether mal mediates a post-translational modification of the XDH and A0 proteins, we constructed several mal heteroallelic complementing stocks of Drosophila in which the third chromosomes were co-isogenic. Since all lines were co-isogenic for the XDH and A0 structural genes, any variation in these enzymes seen when comparing these stocks must have been produced by post-translational modification by mal. We examined the XDH and A 0 proteins in these stocks by gel-sieving electrophoresis, a procedure that permits independent characterization of a protein's charge and shape, and is capable of discriminating many variants not detected in routine electrophoresis. In every mal heteroallelic combination, there is a significant alteration in protein shape, when compared to wild type. The magnitude of differences in shape of XDH and AO is correlated both with differences in their enzyme activities and with differences in their thermal stabilities. As the body of this variation appears heritable, any functional differences resulting from these variants are of real genetic and evolutionary interest. A similar post-translational modification of XDH and A0 by yet another locus, lxd, was subsequently documented in an analogous manner. The pattern of electrophoretic differences produced by mal and lxd modification is similar to that reported for electrophoretic "alleles" of XDH in natural populations. The implication is that heritable variation in electrophoretic mobility at these two enzyme loci, and potentially at other loci, is not necessarily allelic to the structural gene loci.


Genetics ◽  
1981 ◽  
Vol 98 (4) ◽  
pp. 817-831
Author(s):  
George Johnson ◽  
Victoria Finnerty ◽  
Daniel Hartl

ABSTRACT Second chromosomes of D. melanogaster were isolated from a single natural population, and 40 were analyzed by gel-sieving electrophoresis for the presence of polymorphic loci on chromosome 2 that act to modify xanthine dehydrogenase and/or aldehyde oxidase, whose structural genes map to chromosome 3. Clear evidence of polymorphism for one or more xanthine dehydrogenase modifier loci was obtained.


1978 ◽  
Vol 20 (4) ◽  
pp. 489-497 ◽  
Author(s):  
Eva M. Meidinger ◽  
John H. Williamson

Four different genes are known to affect aldehyde oxidase activity (AO) in Drosophila melanogaster. Mutants at each of these loci eliminate AO activity and simultaneously eliminate detectable AO-crossing reacting material (AO-CRM) even though only one is the structural gene for AO (Aldoxn). The other three genes (cin1, lxd and mal) coordinately "control" the levels of activity of AO and two related enzymes, xanthine dehydrogenase (XDH) and pyridoxal oxidase (PO). Contrary to their effects on AO-CRM, neither of these three mutants eliminate XDH-CRM. A model of interaction of these enzymes and genes controlling their activities is discussed.


Science ◽  
1960 ◽  
Vol 131 (3416) ◽  
pp. 1810-1811 ◽  
Author(s):  
Edward Glassman ◽  
William Pinkerton

Two "allelic" Drosophila melanogaster mutants which are deficient in xanthine dehydrogenase can complement one another in heterozygotes. This complementation is due to the production of small amounts of xanthine dehydrogenase, enough of which is present to restore the normal eye color. However, not enough of the enzyme is present to produce normal amounts of the enzyme products, or to reduce the accumulation of the enzyme substrates to levels found in wild-type flies.


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